I will say this:
Please do your research before purchasing these lenses online. They are a lot of fake circle lenses that are manufactured with unsafe ingredients and can do serious damage to the eye. So, before you click purchase on a website, make sure that they can provide you with proof, certificates from the manufacturer allowing them to sell their lenses, and the like.
Not to mention, they are scammers out there . . . with the growing popularity of the lenses, they are people out there who will take your money and not send your lenses, or send you fake ones.
I suggest reading through the Circle Lens thread on Soompi.com. It may be a lot of pages to read through but the information provided in that thread is valuable and extremely important when considering this.